• Korean Journal of Veterinary Research
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• v.46 no.4
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• pp.315-322
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• 2006

Ethanol abuse is associated with liver injury, neurotoxicity, modulation of immune responses, and increased risk for cancer, whereas moderate ethanol consumption exerts protective effects against liver injury. However, the underlying signal transduction mechanisms of insulin-like growth factors (IGFs) which play an important regulatory role in various metabolism mechanisms are not well understood. We investigated the effects of ethanol-induced p42/44 activity on IGF-I secretion, IGF-I receptor and IGFBP-1 secretion using radioimmunoassay and western blotting in primary cultured rat hepatocytes. The p42/44 activity, IGF-I secretion and IGF-I receptor activity significantly accelerated compared to control at 10 and 30 min after 200 mM ethanol treatment, but then it became suppressed at 180 min. In contrast, IGFBP-1 secretion was inhibited compared to control at 30 min after 200 mM ethanol treatment, but increased at 180 min. The IGF-I secretion, IGF-I receptor and p42/44 activity at 30 min after 200 mM ethanol treatment accelerated with increasing ethanol concentration but IGFBP-1 secretion inhibited (p<0.05). The increased IGF-I secretion, inhibited IGFBP-1 secretion and IGF-IR activity by ethanol-induced temporal p42/44 activity at 30 min after ethanol treatment was blocked by treatment with PD98059. Alcohol dehydrogenase (ADH) inhibitor, 4-methylpyramazole blocked the changes of IGF-I secretion, IGFBP-1 secretion, and IGF-IR activity by ethanol-induced p42/44 activity at 30 and 180 min. Taken together, these results suggest that ethanol is involved in the modulation of IGF-I and IGFBP-1 secretion and IGF-IR activity by p42/44 activity in primary cultured rat hepatocytes. In addition, changing of p42/44 activity by ethanol was caused with ADH.

• The Korean Journal of Physiology and Pharmacology
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• v.6 no.3
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• pp.165-169
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• 2002

We have previously demonstrated that phytoestrogens isolated from safflower seeds significantly attenuated bone loss in ovariectomized rats, and directly stimulated proliferation and differentiation of cultured osteoblastic cells. In an attempt to elucidate underlying cellular mechanisms, in the present study we investigated effects of $17{\beta}-estradiol\;(E_2)$ and phytoestrogens such as matairesinol and acacetin, a type of lignan and flavonoid, respectively, on activation of mitogen activated protein (MAP) kinases, extracellular signal-regulated kinase 1 (ERK1) and ERK2, in cultured osteoblastic ROS 17/2.8 cells. Western blot analysis with anti-MAP kinase antibody showed that a wide range concentrations $(10^{-14}\;to\;10^{-6}\;M)\;of\;E_2$ as well as both phytoestrogens induced rapid and transient activation of ERK1/2 through phosphorylation within minutes. Maximum activation of MAP kinases by $E_2$ and phytoestrogens were observed at 10 and 15 min, respectively. $E_2-induced$ phosphorylation of ERK1/2 returned to the control level at 30 min, whereas phytoestrogen-induced phosphorylation was maintained at high level until 30 min. PD-98059, a highly selective inhibitor of MAP kinase, prevented phosphorylation of ERK1/2 in the cells treated either with $E_2$ or phytoestrogens. To examine a possible involvement of estrogen receptor in the activation process of MAP kinase, Western blot analysis was performed in the presence and absence of the estrogen receptor antagonists, ICI 182,780 and tamoxifen. These antagonists blocked MAP kinase phosphorylation induced not only by $E_2,$ but also by the phytoestrogens. To the best our knowledge, this study is the first to demonstrate that phytoestrogens such as flavonoid and lignan extracted from safflower seeds produce a rapid activation of MAP kinase, at least partially via membrane estrogen receptor of the cultured osteoblastic cells.

• Analytical Science and Technology
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• v.15 no.1
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• pp.31-35
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• 2002

A useful receptor for the sensing of ${CIO_4}^-$ species with remarkable selectivity has been developed. The hypersensitive interaction between a host and a guest has been investigated for the complex $[Pd(Me_4en)(Py_2S){\cdot}2ClO_4]_4$ ($Me_4en$ = N,N,N',N'-tetramethylethylenediamine; $Py_2S$ = 4,4'-dipyridyl sulfide). The pyridyl moiety of $Py_2S$ exhibits two sets of $^1H$ resonances that are delicately dependent upon temperature, concentration, and media. The nonrigidity has been explained in terms of an electrostatic equilibrium between the tetrameric host and the ${CIO_4}^-$ guest. The equilibrium is a useful method for the detection of ${CIO_4}^-$ anion with remarkable selectivity via "a restricted guest within a big host" in aqueous solution.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.2
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• pp.139-147
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• 2013

Lysolipids such as LPA, S1P and SPC have diverse biological activities including cell proliferation, differentiation, and migration. We investigated signaling pathways of LPA-induced contraction in feline esophageal smooth muscle cells. We used freshly isolated smooth muscle cells and permeabilized cells from cat esophagus to measure the length of cells. Maximal contraction occurred at $10^{-6}M$ and the response peaked at 30s. To identify LPA receptor subtypes in cells, western blot analysis was performed with antibodies to LPA receptor subtypes. LPA1 and LPA3 receptor were detected at 50 kDa and 44 kDa. LPA-induced contraction was almost completely blocked by LPA receptor (1/3) antagonist KI16425. Pertussis toxin (PTX) inhibited the contraction induced by LPA, suggesting that the contraction is mediated by a PTX-sensitive G protein. Phospholipase C (PLC) inhibitors U73122 and neomycin, and protein kinase C (PKC) inhibitor GF109203X also reduced the contraction. The PKC-mediated contraction may be isozyme-specific since only $PKC{\varepsilon}$ antibody inhibited the contraction. MEK inhibitor PD98059 and JNK inhibitor SP600125 blocked the contraction. However, there is no synergistic effect of PKC and MAPK on the LPA-induced contraction. In addition, RhoA inhibitor C3 exoenzyme and ROCK inhibitor Y27632 significantly, but not completely, reduced the contraction. The present study demonstrated that LPA-induced contraction seems to be mediated by LPA receptors (1/3), coupled to PTX-sensitive G protein, resulting in activation of PLC, PKC-${\varepsilon}$ pathway, which subsequently mediates activation of ERK and JNK. The data also suggest that RhoA/ROCK are involved in the LPA-induced contraction.

• Molecules and Cells
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• v.40 no.5
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• pp.371-377
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• 2017

Despite the importance of the receptor activator of nuclear factor (NF)-kappaB ligand (RANKL)-RANK signaling mechanisms on osteoclast differentiation, little has been studied on how RANK expression is regulated or what regulates its expression during osteoclastogenesis. We show here that insulin signaling increases RANK expression, thus enhancing osteoclast differentiation by RANKL. Insulin stimulation induced RANK gene expression in time- and dose-dependent manners and insulin receptor shRNA completely abolished RANK expression induced by insulin in bone marrow-derived monocyte/macrophage cells (BMMs). Moreover, the addition of insulin in the presence of RANKL promoted RANK expression. The ability of insulin to regulate RANK expression depends on extracellular signal-regulated kinase 1/2 (ERK1/2) since only PD98059, an ERK1/2 inhibitor, specifically inhibited its expression by insulin. However, the RANK expression by RANKL was blocked by all three mitogen-activated protein (MAP) kinases inhibitors. The activation of RANK increased differentiation of BMMs into tartrate-resistant acid phosphatase-positive ($TRAP^+$) osteoclasts as well as the expression of dendritic cell-specific transmembrane protein (DC-STAMP) and d2 isoform of vacuolar ($H^+$) ATPase (v-ATPase) Vo domain (Atp6v0d2), genes critical for osteoclastic cell-cell fusion. Collectively, these results suggest that insulin induces RANK expression via ERK1/2, which contributes to the enhancement of osteoclast differentiation.

• The Korean Journal of Physiology and Pharmacology
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• v.27 no.3
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• pp.241-256
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• 2023

Although chimeric antigen receptor T cell (CAR-T) is a promising immunotherapy in hematological malignancies, there remain many obstacles to CART cell therapy for solid tumors. Identifying appropriate tumor-associated antigens (TAAs) is especially critical for success. Using a bioinformatics approach, we identified common potential TAAs for CAR-T cell immunotherapy in solid tumors. We used the GEO database as a training dataset to find differentially expressed genes (DEGs) and verified candidates using the TCGA database, obtaining seven common DEGs (HM13, SDC1, MST1R, HMMR, MIF, CD24, and PDIA4). Then, we used MERAV to analyze the expression of six genes in normal tissues to determine the ideal target genes. Finally, we analyzed tumor microenvironment factors. The results of major microenvironment factor analyses showed that MDSCs, CXCL1, CXCL12, CXCL5, CCL2, CCL5, TGF- β, CTLA-4, and IFN-γ were significantly overexpressed in breast cancer. The expression of MST1R was positively correlated with TGF- β, CTLA-4, and IFN-γ. In lung adenocarcinoma, MDSCs, Tregs, CXCL12, CXCL5, CCL2, PD-L1, CTLA-4, and IFN-γ were significantly overexpressed in tumor tissues. The expression of MST1R was positively correlated with TGF- β, CTLA-4, and IFN-γ. In bladder cancer, CXCL12, CCL2, and CXCL5 were significantly overexpressed in tumor tissues. MST1R expression was positively correlated with TGF- β. Our results demonstrate that MST1R has the potential as a new target antigen for treating breast cancer, lung adenocarcinoma, and bladder cancer and may be used as a progression indicator for bladder cancer.

• Molecular & Cellular Toxicology
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• v.2 no.1
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• pp.15-20
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• 2006

Genistein is a potent, plant-derived isoflavone that displays estrogenic activity at low concentrations but inhibits proliferation at high amounts. However, the molecular mechanism of genistein is not completely understood. In the present study, the biphasic effects (estrogenic and antiestrogenic activity) of genistein on the growth of MCF-7 cells were identified. Genistein within a low range of concentration, $1-10\;{\mu}M$, stimulated proliferation, while $50-100\;{\mu}M$ caused apoptotic cell death. Additionally, genistein at a low concentration induced estrogen receptor (ER)-mediated gene expression and ER phosphorylation. When pre-treated with PD98059, an MEK inhibitor, ER-mediated gene expression and ER phosphorylation by genistein were noticeably increased. However, the increased gene expression and phosphorylation did not enhance cell proliferation. Moreover, it was observed that ER-mediated signaling performs an important role in the MAPK pathway. The proliferation and apoptosis in genistein-treated MCF-7 cells were partially dependent on the Bcl-2 level. The addition of IC1 182, 780, an estrogen receptor antagonist, inhibited Bcl-2 expression induced by genistein. This study suggests that there is a close relationship between Bcl-2 and the ER signaling pathways in MCF-7 cells.

• IMMUNE NETWORK
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• v.21 no.6
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• pp.42.1-42.20
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• 2021

Eosinophils play critical roles in the maintenance of homeostasis in innate and adaptive immunity. Although primarily known for their roles in parasitic infections and the development of Th2 cell responses, eosinophils also play complex roles in other immune responses ranging from anti-inflammation to defense against viral and bacterial infections. However, the contributions of pattern recognition receptors in general, and NOD-like receptors (NLRs) in particular, to eosinophil involvement in these immune responses remain relatively underappreciated. Our in vivo studies demonstrated that NLRC4 deficient mice had a decreased number of eosinophils and impaired Th2 responses after induction of an allergic airway disease model. Our in vitro data, utilizing human eosinophilic EoL-1 cells, suggested that TLR2 induction markedly induced pro-inflammatory responses and inflammasome forming NLRC4 and NLRP3. Moreover, activation by their specific ligands resulted in caspase-1 cleavage and mature IL-1β secretion. Interestingly, Th2 responses such as secretion of IL-5 and IL-13 decreased after transfection of EoL-1 cells with short interfering RNAs targeting human NLRC4. Specific induction of NLRC4 with PAM3CSK4 and flagellin upregulated the expression of IL-5 receptor and expression of Fc epsilon receptors (FcεR1α, FcεR2). Strikingly, activation of the NLRC4 inflammasome also promoted expression of the costimulatory receptor CD80 as well as expression of immunoregulatory receptors PD-L1 and Siglec-8. Concomitant with NLRC4 upregulation, we found an increase in expression and activation of matrix metalloproteinase (MMP)-9, but not MMP-2. Collectively, our results present new potential roles of NLRC4 in mediating a variety of eosinopilic functions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.5
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• pp.649-656
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• 2015

The protective effect of zinc against cortisol-induced cell injury was examined in rainbow trout gill epithelial cells. Cells exposed to cortisol for 24 h showed increased leakage of lactate dehydrogenase (LDH) as well as decreased cell viability in a dose-dependent manner. Treatment with zinc ($100{\mu}M$ $ZnSO_4$) reduced the severity of both LDH release and cell death as well as protected cells against cortisol-induced caspase-3 activation, indicating reduction of apoptosis. Cortisol-induced cell death, leakage of LDH, and caspase-3 activation were blocked by the glucocorticoid receptor antagonist Mifepristone (RU-486), suggesting that cell injury was cortisol-dependent. In addition, we studied the effect of zinc on the expression of antioxidant genes such as metallothionein A (MTA), metallothionein B (MTB), glutathione-S-transferase (GST), and glucose-6-phosphate dehydrogenase (G6PD) during cortisol-induced cell injury. MTA, MTB, GST, and G6PD mRNA levels increased after treatment with zinc or cortisol, separately or in combination. Higher mRNA levels of MTA, MTB, GST, and G6PD were detected when cells were treated with $100{\mu}M$ $ZnSO_4$ and $1{\mu}M$ cortisol in combination at the same time compared to treatment with zinc or cortisol separately. Cells treated with zinc showed increased intracellular free zinc concentrations, and this response was significantly enhanced in cells treated with cortisol and zinc. In conclusion, zinc treatment inhibited cortisol-induced cytotoxicity and apoptosis through indirect antioxidant action.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.2
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• pp.127-132
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• 2013

Ginsenosides, one of the active ingredients of Panax ginseng, show various pharmacological and physiological effects, and they are converted into compound K (CK) or protopanaxatriol (M4) by intestinal microorganisms. CK is a metabolite derived from protopanaxadiol (PD) ginsenosides, whereas M4 is a metabolite derived from protopanaxatriol (PT) ginsenosides. The ${\gamma}$-aminobutyric acid $receptor_C$ ($GABA_C$) is primarily expressed in retinal bipolar cells and several regions of the brain. However, little is known of the effects of ginsenoside metabolites on $GABA_C$ receptor channel activity. In the present study, we examined the effects of CK and M4 on the activity of human recombinant $GABA_C$ receptor (${\rho}$ 1) channels expressed in Xenopus oocytes by using a 2-electrode voltage clamp technique. In oocytes expressing $GABA_C$ receptor cRNA, we found that CK or M4 alone had no effect in oocytes. However, co-application of either CK or M4 with GABA inhibited the GABA-induced inward peak current ($I_{GABA}$). Interestingly, pre-application of M4 inhibited $I_{GABA}$ more potently than CK in a dose- dependent and reversible manner. The half-inhibitory concentration ($IC_{50}$) values of CK and M4 were $52.1{\pm}2.3$ and $45.7{\pm}3.9{\mu}M$, respectively. Inhibition of $I_{GABA}$ by CK and M4 was voltage-independent and non-competitive. This study implies that ginsenoside metabolites may regulate $GABA_C$ receptor channel activity in the brain, including in the eyes.